Ink distribution system



Oct. 28, 1941. c s 2,260,364

INK DISTRIBUTION SYSTEM Filed May 18, 1940 5 Sheets-Sheet l 30 31 29 2331 INVENTOR BY 49m. 8 ML KM! ATTORNEYS Oct. 28, 1941. L. B. cAsE INKDISTRIBUTION SYSTEM 3 Sheets-Sheet '2 Filed May 18, 1940 mi. vam-INVENTOR ATTORNEYS IIIHHHHMHHU Oct. 28, 1941.

L. B. CASE INK DISTRIBUTION SYSTEM Filed May 18, 1940 3 Sheets-Sheet I 35A! ETY VALVE 61' 1 R J STEAM 31 E z? 1 INVENTOR iii-:53; M :::J -J "6.724, BY I [c -mu ATTORN EYS Pa tented Oct. 28, 1941 2,260,364 m1;msrnmu'rros srsmu Lynn B.

John

Case, New Brunswick, N. 1., assignor to Waldron Corporation, NewBrunswick,

N. 1., a corporation of Jersey Application May 18, 1940, Serial No.335,924 8 Claims. (01. 101-216) This invention relates to inkdistribution systems for printing presses, particularly of theletterpress type. j

Heretofore, commercial letterpress printing has involved the use ofprinting inks which have the necessary fluidity and working consistencyat normal press room temperatures. The ink is wet when printed on thepaper and the setting or drying of the print is eflected by oxidation orpolymerization of an oily constituent of the ink, or by evaporation ofsolvents or carriers from the ink or' by absorption of the ink into thepaper, or by a. combination of two or more of these. Newspaper printingaccording to this process is objectionable in that the first impressionprinting on one side of the paper is inferior to the second impressionprinting on the other side of the paper; smearing and marring occurfrequently during passage of the printing web over angle bars andfolders; offsetting of the printing on to the impression roller 01'tympan of the press occurs and the smearing tendency of newspaperprinting soils the hands and clothesoi the readers. High speedletterpress printing on comparatively non-absorbent paper stock withquite fluid inks compounded from pigments, binders and volatile solventsrequires heating of the web after each impression in order that most ofthe solvent may be driven off and the print dried sufliciently, topermit immediate second impression or multi-color printing and handlingof the printed matter without serious smearing, offsetting and damage tothe print.

10% or more and a further-expense is involved in the cost of ink asoccasioned by its high solvent and low pigment concentration and its lowcovering power. 4

Letterpress printing processes of the kind heretofore used are subjectto the further disadvantage that the formulae of the inks must beadjusted in accordance with the type and speed of the press, the natureof the medium to be printed on and the ultimate use of the printedmatter. This necessarily involves errors in formulating the inks andresults in non-uniform printing quality. Furthermore, particularly wherethe drying of the print is effected by oxidation or evaporationofvolatile solvents, the

workability of the ink on the press and its drying 1 characteristics aresubject to change, thereby causing non-uniformity in the printingprocess and requiring frequent adjustment of the ink formulae.Non-uniformity of operation also, is caused by changing weatherconditions in the pressroom and the variable moisture content of thepaper.

Recently there has been developed a letterpress process which involvesthe use of an ink which is solid at normal pressroom temperatures and'melts to a fluid consistency suitable for letterpress printing'atelevated temperatures, that is,

In very high speed work, use is often made of inks having solvents whichare volatile only at high-temperatures and an intense heating of theprinted web'is carried out after each impression to drive of! solvents,the heating being at temperatures which would inevitably burn the paperit not carried out very quickly. Such a process imposesobjectionable.complications, difliculties and expense into printingpractice. Complicated equipment must be provided for heating the printand the web. The web must be allowed to cool between impressions,necessitating additional lead over the normal of as high as 10 to feetand difliculties are encountered in obtaining I proper registration ofcontiguous'or superimposed prints due to dimensional changes invthe-webcaused bythe heating and cooling operations and dehydration of thepaper. The high heating temperatures and solvent fumes create fire andhealth hazards. Also, an inordinate amount of the paper stock is damagedin practice such that wastage of paper often amounts to as much astemperatures in excess of 1'15 F. In this process,

the printed ink films are set instantaneously when printed withoutencountering the abovementioned difliculties of known letterpressprocesses. The ink is heated to an elevated temperature, giving it thedesired molten consistency for working on the press and the inkingmechanisms and the printing form of the printing-press also are heatedto elevated temperatures. The ink in molten condition is applied to theprinting surface of the form in thin films which adhere to the printingsurfaces at elevated printing temperatures even though the films of inkare quite fluid and the form may be moving at high speed. A sheet or webto be printed is impressed by the inked form, the sheet or web being atordinary pressroom temperatures or at any other temperatures which arelow in relation to the temperature of the molten ink. In this way, theink is printed from the relief surfaces of the form onto the sheet orweb in thin hot films and the extraction of heat from these thin filmsinto the web causes the print to set by freezing instantaneously uponleaving the printing surfaces. Further cooling of the resultant printingeither by natural cooling or by artificial cooling in high speedprinting work produces a finished print immediately after the printingOperation, which is rigid and resistant to smearing, marring and oil?-setting during succeeding impressions and during the folding, stackingand assembling of the printed matter in further operation of the press.

means for conditioning the ink to deliver it to the plate cylinder atthe proper temperature and to so equip the machines involves theprovision of heating means in the ink distribution systems.

' Such systems consist essentially of an ink fountain or ink-furnishingelement, together with a plurality of hollow metal rollers cooperatingwith a plurality of rubber or composition rollers to convey the ink fromthe fountain or furnishing element to the plate cylinder andsimultaneously work it into-proper consistency for application to thetype on the plate cylinder.

An object of this invention is the provision of heating equipment in theink distribution system of such character that it is effective to heatthe ink in the fountain to proper temperature within anarrow-predetermined range and maintain the ink within said temperaturerange until the ink is applied by the plate cylinder to'the paper.

According to this invention, means are provided for circulating hotliquid, preferably hot water, through some, or preferably all, of thehollow metal rollers of the ink distributing system and the printingcylinder and in heat exchange relation to the ink fountain or inkfurnishing element. 'The printing cylinder and each heated roller ismaintained full of hot' liquid so that heat is constantly supplied'tothe entire inner peripheral surface, and the hot liquid is caused toflow therethrough. at such rate that a heat balance is maintained. Therate of fiow of the hot liquid is controlled by the size of the outletorifice which is-so dimensioned that the heat dissipation is balanced bythe heat supplied by the liquid. The piping for effecting circulation of:the hot liquid is so arranged that the direction of flow of the hotliquid alternates in the rollers and cylinder in the order of contact bythe ink film, thereby effecting substantially uniform distribution ofheat supply laterally| across the ink film, resulting in substantiallyuniform temperature laterally of the film. Means are provided in thecirculation system for effecting removal of air or other gas from thecirculating liquid to prevent air binding and its attendantconsequences. when water is used as the heating liquid, temperatures inexcess of 212 F. are obtainable by operation of the system undersuitable super-atmospheric pressure. If the system is operated at apressure higher than pounds above atmospheric pressure, specialequipment is required, but for lower pressures standard equipment isused. Instead of using hot water under pressure, where temperatures inexcess of 212 F..are desired, use may be made of well-knownliquidshaving sufiiciently high boiling points under either atmosphericor superatmospherlc pressure.

Other objects, novel features and advantages .of this invention willbecome apparent from the following specification and accompanyingdrawings, wherein:

Fig. Us a diagrammatic sectional view through an ink distributing systemembodying the invention;

Fig. 2 is a plan view thereof;

Fig. 3 is a schematic view of said system illustrating one form ofliquid heating equipment; I

Figs. 4 and 5 illustrate other forms of heating equipment for thesystem;

Fig. 6 is a diagrammatic view of a system operating under pressures inexcess of 15 pounds above atmospheric, and

Fig. 7 is a diagrammatic view of a modified pressure-type system.

In Fig. 1 is illustrated a typical ink distribution system consisting ofa plurality of rotatable hollow metal rollers R and R1, a plurality ofrubber or composition rollers R2, an educator roller R: and a fountainroller R4. Means (not shown) are provided for rotating said rollers intimed relation and for effecting axial vibration of certain of saidrollers, all as is standard practice in such ink distribution systems.The fountain roller R4 is partially immersed in a pan or fountain F andcertain of the rollers R2 contact the print ing surface on the printingcylinder P, between which and the impression cylinder 0 passes a web Wof paperor other similarmaterial to be printed. A jacket J partiallyencloses the pan or 1 fountain F and in the jacket J is arranged a pipeor a pipe coil ill. The Jacket J is filled with suitable liquid foreffecting transfer of heat from the coil Ill to the pan F and itscontents. Ink is delivered by the eductor R: from the fountain roller R1to the roller R. From the roller R, ink issupplied by the rollers R2 tothe two rollers R1 and through additional rollers R: from the rollers R1to the printing cylinder P.

A header consisting of a cross-pipe II and two arms l2 and I3 issupplied with hot liquid through a pipe l4. Pipes l5, l6 and I! leadfrom the arm 12 respectively to one end of the coil l0, one end of theroller R and one end of the printing cylinder P. Pipes l8, l9 and 20lead from the arm 13 to the opposite ends of the fountain roller R4 andboth rollers R1. A discharge header consists of a cross-pipe 2| and twoarms 22 and 23 and liquid is discharged from this header through thepipe24. Pipes 2!, 26 and 21 lead respectively from the opposite ends ofthe coil l0, roller R andv printing cylinder to the branch 22, and pipes28, 29 and 30 lead respectively from the opposite ends of the fountainroll R4 and both rollers R1 to the arm' 23. The direction of flow in thecoil II), the roller R and the cylinder P is opposite tothe direction offlow in the roller R4 and the rollers R1.

' Each of the aforementioned pipes is connectedto the associated rolleror cylinder by a standard coupling which permits free rotation relativeto the pipe. Such a coupling is standard article of merchandise and isnot herein disclosed in detail as the particular construction of suchcoupling forms nopart of the present invention.

The rate of fiow of hot liquid through the coil I 0, each distributionroller and the printing cylinder is controlled by the outlet orificetherefor.

- 'Such orifice may be of fixed size or may be in the nature of a valveII, whereby the rate offlow may be varied. In each case, the inletorifice is of larger area than the outlet orifice and has no function incontrolling the rate of flow.

the

air pockets or vacuum in the cylinders as liquid is always suppliedthereto it is removed therefrom.

Referring now to Fig. 3, the pipe 24 leads to inlet of a tank '1', theoutlet of which corn-' municates with the inlet of a pump B and theoutlet of said pump communicates with the pipe l4. Operation of'the pumpB withdraws liquid from the tank T and supplies such liquid through thepipe l4 to the coil ll, the distribution rollers and the printingcylinder from which the liquid is returned to the tank through the pipe24. A steam coil arranged in the tank T is supplied with steam throughapipe 33 from any suitable source (not shown) and a pipe 34 returnscondensate from the coil to such source. A thermostat 35, arranged inthe tank 32, operates a valve 36 by which the supply of steam to thecoil 32 is controlled to maintain the liquid at constant temperature.

A pipe 31 leads from the top of the tank T to 'a second'tank T1 at ahigher elevation than the tank T, the tank T1 being provided with an airvent 38. A valve-controlled liquid supply pipe 39 communicates with thepipe 31 below the The operating pressure of the system the leyel of theliquid in'the tank Ti, which must be at least high enough to possibilityof the occurrence of a at least as fast as.

' some instances not more r and cylinder in the order of contact by theink.

than 2 F. between the opposite ends thereof. The heat supplied to therollers and the plate cylinder is so distributed and balanced that thereis little or no temperature differential, either laterally orcircumferentially, along the surface of any roller or the cylinder oralong the ink film. This is accomplished (1) by-maintaining a largemobile or self-equalizing mass of heat in each roller and the cylinderin the form of a body of hot liquid (2) by maintaining at a constanttemperature all liquid circulated into the rollers and the cylinder (3)by keeping at a minimum (not more than F. and in than 2 F.) thediflerential between the temperature of the liquid and the desiredtemperature of the ink (4) by keeping the rate of liquid circulation,through the use of ample pumping capacity, high enough to preventsubstantial drop in the liquid temperature during its passage throughany roller or the cylinder (5) by selecting an outlet orifice size forthe rollers and cylinder in relation to the rate of liquid circulationso that the mass of liquid in each roller and the cylinder is constantlysubject to uniform and positive pressure. and (6) by alternating thedirection of flow of the circulated liquid through the various rollersIn this way, the'ink may be maintained at, subinsure complete filling oithe rollers and cylinder. Figs. 4 and 5' illustrate modified .forms ofequipment for heating the liquid in the tank T. In the modification ofFig. 4, steam is introduced into the interior of the tank, through theextension 33a of the pipe ".and the valve It is operated by thethermostat II to regulate the amount of steam supplied to maintain theliquid in the tank at the proper temperature. Air introduced into thetank withthe steam is vented through the pipe In the modification ofFig. 5, a burner 40, preferably an oil burner or gas burner, is arrangedin the bottom ofthe tank and is supplied with, fuel through the pipe 4iequipped with a valve 42. The combustion. gases from the burner passthrough tubes 43 arranged in .the tank and the flue 44, the combustiongases relation to the liq- The valve 42 is operated by a thermostat 35to re ate the flow of fuel to the burner to maintain the liquid in thetank T at proper temperature.

In the operation of the in the rollers is dissipated in uid and iscarried thereby into the tank T. through the pipe 31 and carried intothe system system, any air trapped the circulating liq- The liquid in.the tank 'r is maintained at conxnake-up'liquid introduced the surfaceof the I stant temperature by operation of the valve 40 by the thermos't 35. Constant temperature liquid is thus supplied to the coil III, theplate cylinder P and the rollers 01 the distribution system. The rate offlow through each roller and the printing cylinder is controlled by therespective outlet orifices to be such as to supply sufilcient heatthereto to maintain a heat balance therein with a temperaturedifferential of not more than 10 F. and preferably of not morestantially the same desired temperature from its departure from thefountain until after it is applied to the web.

The maximum temperature to which the liquid in the tank can be heated isdetermined by the boiling point of the liquid'at the operating pressureof the system as above such temperature vaporization of the liquid willoccur. Usually fifteen pounds above atmospheric pressure is the maximumallowed plumbing equipment is used, and with water as the heat supplyingliquid, the maximum temperature obtainable at such pressure isapproximately 250 F. and the operating pressure is obtained by havingapproximately 34 feet of liquid head in the tank T1. With other liquidshaving higher boiling points than water, operating temperatures in therange of 250 F. to 50Q F. may be obtained in this system. The liquid maybe heated to temperatures of 212 F. by use of superheated steam as theheat source or by use of the heater illustrated in Fig. 5. 3

g. 6 illustrates a system having an operat-' ing pressure in excess offifteen pounds abov'e' atmospheric. In such a system, the. equipmentused is of the so-cailed pressure vessel type which isv sanctioned bylaw-for highpressures. The pipe 31 is equipped at its upper end with anair vent 45 of-such nature as to permit the escape of air whilepreventing the escape of liquid. A safety valve 46 is connected to thesystem, pref 'erably to the pipe 31, and determines the maxithe system.A

stituted for the cylinder and weight piston such,

for example, as a cylinder with an air chamber. Any suitable liquid maybe used as the heating medium in the above-described system under therequired pressure to maintain the boiling point of such liquid above thedesired operatby law where ordinary in excess from its highest point andat its upper 1 steam through the coil 65 steam is so regulated as to ain the tank at a temperature ing temperature. By use of water as theheating liquid, operating temperatures in the range of 250 F. to 500 F.are obtainable'by maintaining the operating pressure in the range of 30pounds to 679 pounds.

The operation of the system illustrated in Fig. 6 is the same aspreviously described, except that the operating are higher. The rate offlow through the various units is controlled by the outlet orifices 3|to maintain heat balance with a temperature differential not exceedingF. and the direction of flow alternates in successive units. Also, airis removed from the rollers and air introduced into the system withthrough the pipe 31, and air vent 45.

With certain types of thermo fluid inks, the printability thereof issubstantially the same over a fairly wide temperature range and inconnection with the use of such inks close control of the temperature ofthe rolls is not essential, nor is it essential that the rolls be ofsubstantially uniform temperature throughout theirlength. The apparatusillustrated in Fig. 7 is designed for use with such inks. In thisapparatus, a mixture of vapor, air and water is provided'in the 'coill0, printing cylinder P and the ink feedingrollers R and R1. As closeregulation of temperature is not required it is not necessary to providefor high efficiency heat transfer from the heating fluid to the rollersand cylinder. heating fluid be air free as the efiect of the reducedheat transfer efliciency by reason of the presence of air in the fluidis relatively unimportant in the operation of printing with inks of thecharacter above referred to. Also, for similar reasons, it is notessential that the rollers be kept full of substantially constant tem-'perature liquid.

Referring to Fig. 7, the equipment illustrated is of the so-calledpressure vessel type which is sanctioned by law for high pressureoperation. A tank 60 has a vertical pipe 6i leading end the pipe isconnected to the low pressure side of a pressure reduction valve to the'high pressure side of which is attached a water supply pipe 63. Asafety valve 64 is connected to the pipe 6| below the pressure reductionvalve 62. In the tank 60 is preferably provided a heating coil 65through which superheated high pressure steam is circulated by means ofthe pipes 66 and 61 but any other suitable heating means employed. Apipe I 4' leads from the top of the tank ,60 to the supply header lldescribed in connection with the previous figures, while a pipe 24'leads from the discharge header'fl, also previously described, .to theinlet port of a pump ,3, the outlet port of which discharges into thetank 60.

In operation, the tank 60 contains water under super-atmosphericpressure. Whenever the pressure in the system drops below that for whichthe valve 62 is set, additional water is automatically introduced intothe system tobring the pressure up to the predetermined value. Thesafety valve 64 is set to function at some pressure in excess of thepredetermined pressure just referred to.-

The water in the tank 60 is heated by passing and the supply of maintainthe water predetermined temperature. The

the liquid escapes Therefore, it is not essential that the maybepressures and temperatures maintain therein a body maintained in thetank 60 is sufto the various units of the ink distribution system. Inthe ink distribution system, the vapor is condensed and the condensateis withdrawn through the pipe 24' and is returned to the tank 60 by thepump B. in the rollers and cy der depends upon the location of theoutlet therefrom. However, in any event, each roller will contain acertain amount of condensate together with air and vapor. Any airescaping from the rollers is returned to the tank 60 along with thecondensate and air. as well as vapor, passes from the tank 60 to thedistribution system. In a modified form, a vapor trap may be substitutedfor the pump 3' in which event the condensateis not returned to the tank60 but is allowed to flow to some source of low pressure, such, forexample, as the sewer.

I claim:

1. In letterpress printing with ink solid at normal pressroomtemperatureand liquid at elevated temperature wherein the ink isliquefied byheating, supplied from a fountain andtransferred in film form to ahollow printing cylinder by a distribution system including a pluralityof hollowrollers, the method which comprises recirculating a definitevolume of liquid in heat exchange relation to the ink fountain andthrough said rollers and cylinder in parallel streams with the directionof liquid flow alternating in the rollers and cylinder in' the order ofcontact by the ink film, maintaining said liquid at suflicient pressurethat its boiling'pqint exceeds the printing temperature of the ink,heating said liquid to a temperature exceeding the printing temperatureof the ink and exceeded by the boiling point of the liquid, controllingthe outflow of liquid from said rollers and cylinder to maintain thereina body of liquid in contact with entire inner surfaces of said rollersand cylinder, and regulating the flow rate through said rollers andcylinder to maintain heat balance therein with not more than 10 F.diflerential between the inlet and outlet ends thereof.

2. In'letterpress printing with ink solid at normal pressroomtemperature and liquid at elevated temperature wherein the ink isliquefied by heatin film tribution system including a plurality ofhollow rollers, the method which comprises recirculating a definitevolume of liquid in heat exchange relation to the ink fountain andthrough said rollers and cylinder in parallel streams with the directionof liquid flow alternating in the rollers and cylinder in the order ofcontact by the ink fllm, heating said liquid to a temperature in therange of F. to 250 F., controlling the outflow of liquid from saidrollers and cylinder to of liquid in contact with the entire innersurfaces of said rollers and cylinder, and regulating the flow ratethrough said rollers and cylinder to maintain heat balance therein withnot more than 10 F. diflerential between the inlet and outlet endsthereof.

3. In'letterpress printing with ink solid at normal pressroomtemperature and liquid at elevated temperature wherein the ink isliquefied by heating, supplied from a in film form to a hollow printingcylinder by a distribution system including a plurality of hollowrollers, the method which comprises recircu- The amount of condensatefountain and transferred lating a definite volume of liquid in heatexchange relation to the ink fountain and through said rollers andcylinder in parallel streams with the direction of liquid flowalternating in the rollers.

and cylinder in the order of contact by the ink film, maintaining saidliquid at suflicient pressure that its boiling point exceeds theprinting temperature of the ink, heating said liquid to a temperature inthe range of 250 F. to 550 F. prior to supplying the same to saidrollers, cylinder and fountain, controlling the outflow of liquid fromsaid rollersand cylinder to maintain therein a body of liquid in contactwith the entire ner surfaces of said rollers and cylinder, andregulating the flow rate through saidrollers and cylinder to maintainheat balance therein with not more than F. differential between the inlet and outlet ends thereof.

4. In letterpress printing with ink solid at normal pressroomtemperature and liquid at elevated temperature wherein the ink isliquefied by heating, supplied from a fountain and transferred in filmform to a hollow printing cylinder by a distribution system including aplurality of hollow rollers, the method which comprises recirculating adefinite volume of liquid inheat exchange relation to the ink fountainand through said rollers and cylinder in parallel streams with thedirection of liquid flow altermating in the rollers and cylinder in theorder of contact by the ink film, controlling the outflow of liquid fromsaid rollers and cylinder to maintain therein a body of liquid incontact with the entire inner surfaces of said rollers and cylinder,heating said liquid to supply a body of mobile liquid in heat exchangerelation with the walls of said rollers and cylinder, flowing the liquidthrough said rollers and cylinder at a rate sufficient to preventsubstantial temperature drop between the ends thereof; and maintainingthe temperature of the liquid supplied to the rollers and cylinder notmore than 30 F. above the desired printing temperature.

5. In a printing press comprising a hollow printing cylinder, an inkfurnisher, means including hollow metal rollers for conveying anink filmfrom said furnisher to said cylinder and a system for circulating liquidthrough said. furnisher, rollers and cylinder; .a closed tank containinga body of liquid, means for heating said body of .liquid, a pump andmanifolds connectin said tank with said ink furnisher, rollers andcylinder for recirculating liquid from said tank in parallel streams inopposite directions through alternate members of said ink furnisher,rollers and cylinder back to said tank to'efiect uniform lateraldistribution. of heat in said film, and means for controlling flowthrough said rollers and cylinder to maintain constant positive pressuretherein exceeding the pressure beyond the outlets therefrom.

6. In a printing press comprising a hollow printing cylinder, an inkfurnisher, means including hollow. metal rollers for conveying an inkfilm from said furnisher to said cylinder and a system for circulatingliquid through said furnisher, rollers and cylinder; a closed tankcontaining a body of liquid, means for heating said body of liquid, apump and manifolds connecting said tank with said ink furnisher, rollersand cylinder for recirculating liquid from said tank in parallel streamsin opposite directions through alternate members of said ink furnisher,rollers and cylinder back to said tank to effect uniform lateraldistribution of heat inxsaid film, means taining a body of liquid, meansfor-heating said body of liquid, a pump and manifolds connecting saidtank with said ink furnisher, rollers and cylinder for recirculatingliquid from said tank in parallel streams in opposite directions throughalternate members of said ink furnisher, rollers and cylinder back tosaid tank to "effect uniform lateral distribution of heat in said film,means for controlling flow through said rollers and cylinder to maintainconstant positive pressure therein exceeding the pressure beyond theoutlets therefrom, means for maintaining the liquid .in said tank atconstant temperature, and means for maintaining the liquid in said tankunder constant super-atmospheric pressure.

8. In a printing press comprising a hollow printing cylinder, an inkfurnisher, means including hollow metal rollers for conveying an inkfilm from said furnisher to said cylinder and a system for circulatingliquid through said furnisher, rollers and cylinder; a closed tankcontaining a body of liquid, means for heating'said body of liquid, apump and manifolds connecting said tank with said ink furnisher, rollersand cylinder for recirculating liquid from said tank in parallel streamsin opposite directions through alternate members of said ink furnisher,rollers and cylinder back to said tank to eifect uniform lateraldistribution of heat in said film, means for controlling flow throughsaid rollers and cylinder to maintain constant positive pressurethereinexceeding the pressure beyond the outfrom said tank.

for automatically venting air LYNN B. CASE.

